The present invention is directed to the preparation of a gamma-chloromethyl-gamma-butyrolactone which is useful as a solvent, for example, for acetylene, epoxy resins, and polyvinyl chloride copolymers and other resins. Previous methods of making lactones in general have been by conversion of gamma-hydroxy acids to gamma-lactones as follows: ##STR1## See, for example, Cason, Principles of Modern Organic Chemistry, Prentice-Hall, Inc., 1966. Morrison and Boyd, Organic Chemistry, 2nd Ed., Allyn and Bacon, Inc., Boston, 1970, give the reaction as follows for the salt of a gamma-hydroxy acid: ##STR2##
Commercially gamma-butyrolactone is made from 1,4-butanediol by oxidative cyclization. However, the diol is believed to first be converted to the hydroxy acid before the cyclization occurs so that the cyclization would be as given in the above equations.
A synthesis of the analogous iodolactone was reported by E. E. Van Tamelen et al, J. Am. Chem. Soc., 76, 2315 (1953). The lactone was made from 4-pentenoic acid and a stoichiometric amount of iodine.